My device (vvx 500 - 5.2.2) is subscribing with expires=3600, but the server overrides the value with 180 (3 min). The device does not set voIpProt.server.x.expires.overlap, so it should default to 60 seconds.
The behaviour I am seeing is that the subscription expires after 3 minutes - as expected, however the device does not try to subscribe again until 4 minutes after that. I expect it to try at the 2 minute mark.
What could be the possible cause?